1. Field of the Invention
The present invention relates to a method of separating products, each connected to a skeleton portion of work via micro joints, from the skeleton portion, and a pair of punch and die used for the above-mentioned method.
2. Description of the Prior Art
In the conventional plate material processing such that products are punched out of work through punch press processing, laser processing, plasma jet processing, etc., a minute non-cut off portion (referred to as a micro joint) is formed at a corner of each product so that the punched-out product will not be separated from a skeleton portion of work. Further, after a sheet of the plate material has been all processed, these micro joints are broken off to separate the processed products from the remaining skeleton portion of the work.
Conventionally, the products processed under connection to the work through the micro joints have been so far separated from the remaining skeleton portion of the work by use of a hammer, by manual work (a worker holds both ends of the skeleton portion by his hands and shakes the skeleton portion up and down), or by cutting off the micro joints away from the skeleton portion by use of a micro joint separator, for instance as disclosed in Japanese Published Unexamined (Kokai) Utility Model Application Nos. 5-13624 and 4-90124.
With respect to the conventional methods of separating the products from the work skeleton portion, the separating work is heavy labor in the case of the manual separation; and the workability is low in the case of the micro joint separator because the micro joints must be separated from the remaining work skeleton portion with the use of a vibrating apparatus. In particular, in the conventional micro joint separating apparatus, automation has been so far difficult because the positional information related to the respective micro joints must be detected, and in addition it is difficult to confirm that products have been separated from the skeleton portion perfectly. Further, in any cases, there exist other problems in that the products are scratched or depressed; large sound noise is generated; and additional works (for assortments or accumulation) are required after the products have been separated.